As complexity and miniaturization in electronic apparatus increases, the need for smaller sizes, higher reliability and the ability to service and assemble under field conditions where the miniaturized apparatus is likely to be used, also increases. In electronic device packaging, the electronic devices are usually mounted on, or are in, a planar, device supporting substrate member with electrical connections to the devices being at the edge of the substrate. The planar substrate is in turn mounted in a fixed position in relation to another planar, external wiring supporting member such as a printed wiring board and interconnections are provided between the conductors on the wiring board and the electrical connections at the edge of the device supporting substrate.
As miniaturization progresses, the electrical connections in electronic packaging systems have become the most fragile and failure prone aspect of the entire system.
Heretofore, much effort in the art has been directed to making those electrical connections using fusion, such as soldering and thermocompression bonding. Where there is a need for assembly and servicing under field type conditions, the precision equipment needed for tightly controlled thermal excursion connections is seldom available. Similarly, under such conditions, equipment for precision positioning of parts is also seldom available.
Under these circumstances, attention is being given in the art to the use of interconnecting arrangements that permit manual assembly and disassembly with minimal temperature and positioning control considerations.
One technique receiving attention in the art involves the use of elastomeric materials that apply constant pressure when distorted. In one such system, elastomeric members provide constant contacting pressure to pin connectors under a frame compressed with a cam mechanism. This is shown in U.S. Pat. No. 4,867,689. In another system, elastomeric properties are employed with highly conductive regions as connecting members. This is shown in U.S. Pat. Nos. 4,643,498 and 4,643,499. The U.S. Pat. No. 4,643,498 patent also shows a slot for holding a substrate. In this type of system, there are limits to control of the dimensions of the conductive region that may affect density and signal response and also may affect positioning where the precise location of the conductive regions is not always visible.
There is a technology involving a flexible tape with an insulating material that supports precisely positioned conductors, known in the art as flex tape, that is well developed to the level of being able to provide precision electrical impedance matching. This technology is employed in U.S. Pat. No. 4,830,623 with a frame type compression system. The flex tape technology is also used in Japan document 59-91677 to provide an interconnection, using pins for attachment into external wiring, with attachment to the conductor pads at the edge of a device supporting substrate being made by clips.